1. Field of the Invention
This invention relates to apparatus for measuring the properties of seawater when the apparatus is released from a vehicle submerged in the sea. The apparatus used to measure the water properties is the well known bathythermograph. These devices when released, are positively buoyant and rise toward the surface. At a predetermined depth the temperature probe is released and falls to the bottom. The probe is connected to the launching vehicle by a thin wire over which the temperature data is sent to the vehicle. When the probe has reached the end of the wire or when the maximum depth desired has been reached, the probe and wire are released to sink to the bottom. As the rate of descent of the probe is known a temperature-depth graph is generated.
Such data is critical for submersibles as they rely on sonar for detection of other vehicles or submerged objects. Sonar requires accurate information on the properties of the ambient water in which the vehicle is operating, and in particular, the temperature-depth relationship.
2. Description of the Prior Art
Current temperature probes when released rise toward the surface and are released to fall back down when a predetermined depth at or near the surface is reached. This is satisfactory when the submerged vehicle is operating in the open sea. However, when the submerged vehicle is operating under an ice flow or an ice cap, current apparatus is unsatisfactory. Often the apparatus is trapped at too great a depth under an ice cap and is not released. This can only be overcome with current apparatus by determining the depth of the ice, which is in itself an inaccurate process, and setting the probe to release at a greater depth of water than the thickness of the ice.
The prior art is best illustrated by the inventor's prior U.S. Pat. No. 3,524,347 and U.S. Pat. application Ser. No. 22,939, filed on Mar. 26, 1970.